Resolved Python module import dependencies (AcademySoftwareFoundation#1595)

This patch adds pybind11::module::import() calls to MaterialX Python C extension modules that depend on other MaterialX Python C extension modules.

The intention is to allow any of the MaterialX Python C extension modules to be imported in any order.

A couple of the Python scripts are updated to remove unused MaterialX imports, and to sort imports alphabetically (which is now possible as the modules import their own dependencies).

Author: StefanHabel

python/Scripts/baketextures.py

@@ -5,9 +5,8 @@
 
 import sys, os, argparse
 from sys import platform
+
 import MaterialX as mx
-from MaterialX import PyMaterialXGenShader
-from MaterialX import PyMaterialXGenGlsl
 from MaterialX import PyMaterialXRender as mx_render
 from MaterialX import PyMaterialXRenderGlsl as mx_render_glsl
 if platform == "darwin":

python/Scripts/generateshader.py

@@ -5,12 +5,13 @@
 '''
 
 import sys, os, argparse, subprocess
+
 import MaterialX as mx
-import MaterialX.PyMaterialXGenShader as mx_gen_shader
 import MaterialX.PyMaterialXGenGlsl as mx_gen_glsl
-import MaterialX.PyMaterialXGenOsl as mx_gen_osl
 import MaterialX.PyMaterialXGenMdl as mx_gen_mdl
 import MaterialX.PyMaterialXGenMsl as mx_gen_msl
+import MaterialX.PyMaterialXGenOsl as mx_gen_osl
+import MaterialX.PyMaterialXGenShader as mx_gen_shader
 
 def validateCode(sourceCodeFile, codevalidator, codevalidatorArgs):
     if codevalidator:

python/Scripts/translateshader.py

@@ -5,15 +5,13 @@
 '''
 
 import sys, os, argparse
-import MaterialX as mx
-
 from sys import platform
+
+import MaterialX as mx
 from MaterialX import PyMaterialXGenShader as mx_gen_shader
-from MaterialX import PyMaterialXGenGlsl as ms_gen_glsl
 from MaterialX import PyMaterialXRender as mx_render
 from MaterialX import PyMaterialXRenderGlsl as mx_render_glsl
 if platform == "darwin":
-    from MaterialX import PyMaterialXGenMsl as ms_gen_msl
     from MaterialX import PyMaterialXRenderMsl as mx_render_msl
 
 def main():

source/PyMaterialX/PyMaterialX.h

@@ -16,4 +16,16 @@
 #include <pybind11/operators.h>
 #include <pybind11/stl.h>
 
+// Define a macro to import a PyMaterialX module, e.g. `PyMaterialXCore`,
+// either within the `MaterialX` Python package, e.g. in `installed/python/`,
+// or as a standalone module, e.g. in `lib/`
+#define PYMATERIALX_IMPORT_MODULE(MODULE_NAME)                               \
+    try                                                                      \
+    {                                                                        \
+        pybind11::module::import("MaterialX." #MODULE_NAME);                 \
+    }                                                                        \
+    catch (const py::error_already_set&)                                     \
+    {                                                                        \
+        pybind11::module::import(#MODULE_NAME);                              \
+    }
 #endif

source/PyMaterialX/PyMaterialXFormat/PyModule.cpp

@@ -15,6 +15,9 @@ PYBIND11_MODULE(PyMaterialXFormat, mod)
 {
     mod.doc() = "Module containing Python bindings for the MaterialXFormat library";
 
+    // PyMaterialXFormat depends on types defined in PyMaterialXCore
+    PYMATERIALX_IMPORT_MODULE(PyMaterialXCore);
+
     bindPyFile(mod);
     bindPyXmlIo(mod);
     bindPyUtil(mod);

source/PyMaterialX/PyMaterialXGenGlsl/PyModule.cpp

@@ -16,6 +16,9 @@ PYBIND11_MODULE(PyMaterialXGenGlsl, mod)
 {
     mod.doc() = "Module containing Python bindings for the MaterialXGenGlsl library";
 
+    // PyMaterialXGenGlsl depends on types defined in PyMaterialXGenShader
+    PYMATERIALX_IMPORT_MODULE(PyMaterialXGenShader);
+
     bindPyGlslShaderGenerator(mod);
     bindPyGlslResourceBindingContext(mod);
 

source/PyMaterialX/PyMaterialXGenMdl/PyModule.cpp

@@ -13,5 +13,8 @@ PYBIND11_MODULE(PyMaterialXGenMdl, mod)
 {
     mod.doc() = "Module containing Python bindings for the MaterialXGenMdl library";
 
+    // PyMaterialXGenMdl depends on types defined in PyMaterialXGenShader
+    PYMATERIALX_IMPORT_MODULE(PyMaterialXGenShader);
+
     bindPyMdlShaderGenerator(mod);
 };

source/PyMaterialX/PyMaterialXGenMsl/PyModule.cpp

@@ -14,6 +14,9 @@ PYBIND11_MODULE(PyMaterialXGenMsl, mod)
 {
     mod.doc() = "Module containing Python bindings for the MaterialXGenMsl library";
 
+    // PyMaterialXGenMsl depends on types defined in PyMaterialXGenShader
+    PYMATERIALX_IMPORT_MODULE(PyMaterialXGenShader);
+
     bindPyMslShaderGenerator(mod);
     bindPyMslResourceBindingContext(mod);
 }

source/PyMaterialX/PyMaterialXGenOsl/PyModule.cpp

@@ -13,5 +13,8 @@ PYBIND11_MODULE(PyMaterialXGenOsl, mod)
 {
     mod.doc() = "Module containing Python bindings for the MaterialXGenOsl library";
 
+    // PyMaterialXGenOsl depends on types defined in PyMaterialXGenShader
+    PYMATERIALX_IMPORT_MODULE(PyMaterialXGenShader);
+
     bindPyOslShaderGenerator(mod);
 }

source/PyMaterialX/PyMaterialXRender/PyModule.cpp

@@ -25,6 +25,9 @@ PYBIND11_MODULE(PyMaterialXRender, mod)
 {
     mod.doc() = "Module containing Python bindings for the MaterialXRender library";
 
+    // PyMaterialXRender depends on types defined in PyMaterialXCore
+    PYMATERIALX_IMPORT_MODULE(PyMaterialXCore);
+
     bindPyMesh(mod);
     bindPyGeometryHandler(mod);
     bindPyLightHandler(mod);